


A Suitable Reward

by SesuRescue (Kigachan)



Series: Papyrus and Grillby doing totally normal couple things on the Surface [7]
Category: Undertale (Video Game)
Genre: Anal Sex, Bets & Wagers, Blow Jobs, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Explicit Language, Explicit Sexual Content, Face-Fucking, Fire Dick, Fontcest, Multi, Oral Sex, Papby, Papysansby, Semi-Public Sex, Sex Toys, Sex Toys Under Clothing, Suit Kink, Teasing, Threesome - M/M/M, Vibrators, sansby - Freeform
Language: English
Status: Completed
Published: 2017-08-16
Updated: 2017-08-16
Packaged: 2018-12-16 01:08:04
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,513
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11818023
Author URL: https://archiveofourown.org/users/Kigachan/pseuds/SesuRescue
Summary: Sans challenges Grillby to a bet.





	A Suitable Reward

**Author's Note:**

> I blame the bulk of this on @Megalotrash for plotting this out with me. 
> 
> Please enjoy my self-indulgent trash based around my two loves; Papysansby and suits.

Grillby examined himself in the mirror, adjusting his tie for the tenth time. Was it straight? Did it match his suit? He had to look perfect tonight.

Yesterday, Papyrus was promoted at work to head chef, and to celebrate Sans suggested that they all go out to a fancy, upscale restaurant. The place had a strict dress code, so Grillby decided to wear a suit that had been sitting in his closet, a gray, slim-fitting one that still fit him after all this time.

He fiddled with his tie again, a nice black one with a navy diamond pattern, as Papyrus walked out of the bathroom, smelling faintly of bleach. Papyrus had chosen a navy suit, and to compliment it he wore a black and grey striped tie. As expected of a skeleton of his caliber, everything laid neat and not a fiber was out of place.

“Do you need assistance?” Papyrus asked, gesturing to Grillby’s tie. He nodded, turning away from the mirror to the skeleton. Papyrus examined his tie, undoing the knot and adjusting the ends to lay against Grillby’s chest so he could re-tie it. “It's a little surprising to learn that you have trouble with ties. I thought it would come easily to you, considering your normal attire.”

“…There's too much fabric involved. Bow ties are easy, but this is difficult,” Grillby muttered, embarrassment evident.

“Well, it just means I get to help you until you learn. There, all done.” Papyrus took a step back to admire his handiwork, gazing through his phalanges as if he was using a camera. “Yep, it's perfect! You look…” Papyrus blushed, orange staining his cheekbones. “Very nice.”

Grillby took a step forward, cradling Papyrus’ skull. _He’s too cute._ “…Thank you, you are also very dashing.” He went in for a kiss, but Papyrus stopped him with a finger to his mouth.

“I used a lot of bleach to make sure my bones were perfectly white for this date, so my skull still needs to dry. I'll be outside waiting for you and Sans, okay?”

Papyrus left the room, leaving Grillby to stand around awkwardly. As if a gift from the gods, Sans called his name from the other room, giving him a reason to leave.

Grillby headed over to the spare room, which Sans had been using to store extra clothing, and his breath caught in his throat when he saw Sans. He knew that the skeleton could clean up if he really wanted to, but _damn._

Unlike the other two, Sans had opted for a simple black pinstripe double-breasted waistcoat instead of a suit top and it was…really working for him. The suit hugged his figure in all the right places, while still maintaining the slight chub the shorter skeleton appeared to like on himself. His tie, a navy and grey color that somehow worked together, was tied perfectly, most likely courtesy of Papyrus.

“heya grillbz. i wanna run something by you, once you get your jaw off the floor.” Sans chuckled.

Flushing, Grillby closed his mouth, using his hand to wipe away some drool that no doubt fell from his mouth. “…Sorry, I…uh…what's up?” Perfect Grillby, real smooth.

“wanna play a game?”

Grillby raised a fiery eyebrow. “…What kind of game?”

“a fun one, with a friendly wager.” Sans grinned. “if i win, you'll pay for our dinner tonight. but, if you win, i’ll pay off my entire tab.”

Grillby gawked at Sans as if he suddenly grew three heads. Him, paying off his tab? It was laughable. “…You wouldn’t do that.”

“i would, if you won; i’m a skeleton of my word. sounds like a _suit_ able reward, doesn’t it?” Sans held out his hand. “so, what do you say pal, you in?”

Grillby considered for a moment; It could've been a prank or a joke. Sans knew that his tab was the only thing to get Grillby really riled up, and has used that in the past to get him to do insane things. Grillby knew Sans knew and yet…the chance to finally beat the short skeleton…it was too good to pass up. He'd win whatever ridiculous thing Sans had cooked up, and then he will finally, finally claim his pride back. He nodded and shook Sans’ hand. “...Okay, I'm in. What’s the game?”

Sans smirked, his permanent smile stretching impossibly far as he pulled out a small box from behind his back. He opened it to reveal a small, glowing blue object, oddly shaped with a flared base. Grillby took a step back in shock.

“…Wait, is that a butt plug?”

“yep, a magic one made exclusively for hot-bodied individuals such as yourself. you're going to last the entire dinner with this in you without cumming.”

“…That’s easy enough.” That didn’t sound easy at all, to be honest, but there was no way in hell he was letting Sans know that.

“i haven't gotten to the best past yet, grillbz.” Sans took a small remote out of his pocket and pressed a button. The box shook as the butt plug buzzed and jittered about. “It vibrates, and I have the remote to control it.”

Suddenly, Grillby wasn't all too sure that he could win this. “…Can I back out?”

Sans’ smile fell for a split second, before returning back to normal. He saddled up beside Grillby and laid a palm against the flat of his back. “i’d never make you do anything you didn't want to do, bud. you can back out if you want but, something tells me you don't want to.”

Ugh, Sans was right. Grillby had always been fascinated with the idea of semi-public sex, and some of his biggest fantasies included Papyrus under his bar, sucking him off without anyone else knowing.  How Sans knew about that kink of his was still up in the air, especially since he never dared talk to anyone about it, never mind entertain the idea of doing it.

“…How did you know?”

“i _might've_ made you talk while you were drunk.”

“…You prick,” Grillby japed, plucking the box from Sans’ hands and reluctantly pulling away from him to walk towards the door. If he was going to do this, he was at least going to make Sans work for it.

Sans put a hand against his ribcage in mock-hurt as he followed Grillby out of the spare room and into the master bedroom. “oh, you wound me. whatever shall i do to make it up to you?”

Grillby sat on the bed, placing the box beside him. He spread out his legs enticingly, patting the space in front of him. “…I'm sure you can figure something out.”

Sans climbed onto the bed and straddled Grillby’s waist, licking his teeth as he took in the delicious view from above.

“whew grillbz, you’re _smoking hot_ in this suit,” Sans whistled. He rubbed over Grillby’s body, putting just enough pressure into his touches to make Grillby squirm.

Grillby rolled his hips, trying to create some friction between their lower halves, but before they could connect Sans lifted his hips out of reach.

“ah ah ah, you gotta be patient.”

Clenching Sans’ tie in his fist, Grillby dragged him down into a kiss. He moaned as it deepened, opening his mouth to tangle his tongue with Sans’. Unsurprisingly, Sans tasted a little bit like ketchup. Eventually, he broke the kiss, pulling his head away to take in some air.

“…Ha…patience isn't really my strong _suit.”_

“man, I love you,” Sans sighed lustfully. He loosened Grillby’s tie desperately, shakily unbuttoning the top few buttons on his dress shirt to latch onto Grillby’s neck with his teeth. Grillby groaned as Sans pulled away to lap at the bite mark with his tongue, the cool ectoplasm soothing his irritated flames.

They rutted against each other as Sans continued biting and licking Grillby’s neck. Grillby groaned at every pass, arching further into Sans as he grinded his hard cock against the other. The combination of sensations soon had Grillby reeling in delight.

“Sans…mmm…feels good.”

Sans backed off, ignoring Grillby’s objections as he slid to the floor. “oops, can't let you enjoy yourself too much before the game starts." He unbuckled Grillby’s belt, opening the pants and slowly pulling them down to his ankles. The boxers followed, leaving Grillby’s bottom half bare and exposing his cock. Sans grabbed and balanced Grillby’s thighs on his shoulder, nuzzling into a fiery leg.

“your leg is so hot, I bet you could fry an egg on it.”

Grillby rolled his eyes, chuckling slightly. “…Come on, comedian, let's hurry up before Papyrus gets mad.”

“ok, ok.” Sans fished around in his pocket, pulling out a small tube of lube and spreading the liquid on his fingers.

Grillby gasped as phalanges brushed across his asshole, the contrasting temperature of the lube sending a small tremor through his body. He moaned low as Sans pushed in a finger, rubbing it against his inner walls. Just as he started getting used to it, Sans entered a second finger.

“…Fuck!” Grillby cried, dick twitching and oozing precum. He scrambled around for something to hold onto, settling on squeezing a pillow between his arms as he tried to stay coherent.

“geez, you're so sensitive. i wonder if i can make you scream…” Sans’ grin turned predatory as he moved his fingers with purpose inside Grillby, searching. Before Grillby could protest, Sans’ fingers brushed against his prostate, making him see stars. He yelled, body convulsing as his nerves went into overdrive to process the jolt to his system. One touch and he was already melting, how was Sans so good at this?

Sans stretched his fingers once more before removing them, making .eye contact as he brought his phalanges to his mouth. He made a show of wrapping his tongue over them, slurping loudly and chuckling at the heated stare Grillby was giving him.

Fingers thoroughly cleaned, Sans reached for the butt plug beside Grillby, slathering it in lube and bringing the tip to his prepped entrance. Grillby nodded, shifting his legs in anticipation. It may have not been Sans’ cock but he needed something, anything in him to quell the ache in his gut.

The plug slowly entered Grillby, his hole expanding to take in the object. He sighed, relaxing as the flared base hit him, signifying that it was all in.

Sans gently lowered Grillby’s legs to the ground, allowing him to stand and get dressed again. As he pulled up his pants, Grillby squirmed, shifting from one foot to the other, trying to get used to having something just sitting in his ass.

“feel weird?” Sans asked.

“... Yeah, really odd.”

“you'll get used to it, i promise. let's go, remember the rules?”

Grillby nodded, and after turning off the lights and grabbing a jacket, they left the apartment to meet with Papyrus.

Upon arriving at the car, Papyrus turned around to face the two of them, his hands clasped around a puzzle book.

“OH! There you two are, I was wondering when you'd come out! Oh, Grillby! Your tie!” Papyrus placed his book in Grillby’s hands as he went about fixing the tie again. “If you're going to fool around, at least fix up after yourselves!”

Grillby blushed, placing a kiss on Papyrus’ jaw. “... I apologi-” Suddenly Grillby cut himself off as the butt plug spurred to life. He gripped Papyrus’ shoulders in panic as he tried not to groan.

“Grillby, are you okay?”

The buzzing stopped, allowing Grillby to regain a grip on his body. He straightened up and released Papyrus. “…Sorry, I uh…pulled a muscle in my leg.”

Papyrus scrutinized Grillby for a few moments, before tilting his head. “Do fire elementals even have muscles?” He checked his watch. “Never mind, let's go. I don't want to be late for our reservation!”

Grillby opened the car door, distinctly avoiding Sans’ shit-eating grin as he got in the passenger side.

The vibrations apparently weren’t loud enough for Papyrus to hear it when he was standing right next to him, and it probably wasn’t too bad to deal with in the long run, either. He was going to wipe that smile off Sans’ face when he won, he just knew it.

 

* * *

 

Eventually, they arrived in the valet parking lot, and Grillby was still confident that he could win their game. Sans had tried to catch him four times in the car on the way to the restaurant, once while he was mid-yawn, but Grillby managed to thwart every attempt flawlessly.

The three of them exited the car, Sans and Grillby idling by as Papyrus ran off to give the valet the keys. While they were waiting, Grillby leaned over to rest his arm on Sans’ shoulder.

“…This game of yours is a snooze fest,” Grillby gloated, yawning to cement his point. Cocking his head to the side, Sans’ eye lights flickered to Grillby.

“oh, you're ready to play for real now?”

“...What are youUUUU-!” The toy turned on, and it much more intense than last time. Grillby struggled to stay standing as his legs shook under him, threatening to topple him over.

Just as soon as it started, everything stopped, allowing Grillby to take a deep breath. His soul thumped wildly in his chest, and he was painfully aware of a new problem he had in his pants. Did this toy have stronger settings that what he had already experienced?

Blushing, Grillby took off his outer jacket, folding it in his arms in front of himself to hide his boner, just in time for Papyrus to come back.

“I gave the valet my keys and a nice tip, so we're all good!” Papyrus set his sights on Grillby, noticing his coat. “Oh, were you feeling too hot to keep your jacket on?”

“... I'm always too hot.” Grillby deadpanned, much to Sans’ delight and Papyrus’ displeasure. Papyrus swatted at him playfully as they headed inside the building.

There was no other way to describe the restaurant other than _lavish_. Every table had small candles in the middle to provide light, giving the restaurant an overall intimate atmosphere. In the middle of the ceiling hung an enormous chandelier, reflecting light off the candles to sparkle and dazzle the otherwise large, dark room.

The three of them stood in the entranceway, their mouths wide open, taking everything in, when a small cough alerted them to the human waiter standing before them with a clipboard.

“Good evening, do you have a reservation?”

Grillby stepped forward. “…It should be under ‘Grillby’.”

The waiter checked the list, confirming it, casting a wary eye at Grillby while he did so. He opened his mouth as if to say something, but after what appeared to be an internal conflict closed it. “Follow me.”

They followed the human waiter past occupied tables to a small, plush booth near the back of the restaurant. Grillby ended up sitting next to Papyrus, with Sans taking the seat in front of him. Papyrus leaned over onto Grillby, throwing his arms around his chest.

“I’m so excited to be here!” Papyrus gushed softly, bringing his voice down to as much of a whisper as he could manage. “Thank you so much for bringing me here!”

“...No probl-AHH!-em,” Grillby yelped, the butt plug pulsing yet again.

Papyrus pulled back, fretting over Grillby. “You’re acting weird, are you sure you’re okay? You don't have to force yourself for my sake.”

The vibrations intensified to a slightly unbearable level, killing any thoughts in Grillby’s head on how to reply. All he could think about was the thrill of his prostate being stimulated by the toy, and his cock becoming uncomfortably hard. Regaining some sense of decency, he kept his mouth shut and quickly nodded his head.

Not convinced, Papyrus moved in close to rest his head against Grillby’s forehead. The proximity of their faces overloaded Grillby’s senses, causing his flames to climb a few inches and flare out.  “Hmmm, you’re not abnormally hot or cold, but you'll let me know if you don’t feel well while we're out, right?” Grillby frantically nodded, praying that he didn’t cum right there at the table. Papyrus seemed to accept the answer as he pulled Grillby into a chaste kiss.

Grillby’s thoughts bordered on sinful as he melted into the kiss, wanting nothing more than to stick his tongue down Papyrus’ non-existent throat and fuck him right there on the table. He surreptitiously rubbed his thighs together, the reverberations from the plug bordering on painful as he got dangerously close. His hand gripped the table hard as he pulled away from Papyrus, a familiar orange blush on his face.

He was one step away from saying fuck it and grabbing Papyrus when the toy stopped, his body slowly easing him back into the real world.

“Sirs?”

They all turned to their waiter, who seemed slightly uncomfortable. “I must ask you to keep a handle on your flames, sir. The other patrons are getting a bit uneasy.” Grillby nodded, embarrassed, as the waiter took out a pen and a notepad. “Now then, what can I get you for your meals?”

Papyrus perked up. “Do you mind if I ask you some questions about the menu?”

While Papyrus was engaged with the waiter, Grillby turned to glare at Sans, the latter feigning innocence with a shrug.

‘…You’re going get us kicked out!’ he mouthed silently. Sans, in response, turned on the vibrator again, forcing Grillby’s head to the table to stop himself from letting out any sounds. This was torture, plain and simple. Why did he agree to this game again? He was so hard he could probably break rocks with his dick right now. All he wanted to do was grab his boyfriends and rush them back to the apartment and-

“Grillby?” Papyrus’ voice interrupted his thoughts. He quickly lifted his head from the table.

“...Yes?” Grillby asked, slightly frazzled.

“What did you want to eat?”

Grillby shied away from the curious glances as he buried his head in the menu to quickly pick something. He could barely process any of the entrees described, the toy against his prostate was just _so good._ What if he just…let go? He was so close already, his toes curling in ecstasy. Wait, fuck, his suit would show everything, wouldn't it?

He lowered his menu to send an S.O.S. to Sans, hoping that his extremely blue face would clue the shorter skeleton in. Knowing he had to choose a meal quickly to avoid too much attention, and not trusting his voice to work properly, he pointed to a random listing on the menu. Right as the waiter left to put their orders in, the vibrator clicked off, leaving Grillby extremely relieved, but frustrated.

He was on edge the entire time as he engaged in conversation with Papyrus, listening to him give a riveting retelling of his promotion. He kept glancing back towards Sans, wondering when he was going to surprise him again. However, he seemed content to listen to his brother, chiming in every now and again with a witty pun.

Soon enough, their food came out, much to Papyrus’ glee. He ordered their popular spaghetti to try, Sans got some sort of burger (where even was that on the menu), and Grillby apparently ordered some sort of noodle dish. Shrugging, he picked up his fork and started eating his meal.

Suddenly, something rubbed against Grillby’s crotch, making him choke. He glowered at Sans, scandalized, as Sans beamed back at him. Both of Sans’ hands were on the table, occupied with eating his food. What else could he be using to terrorize him?

The answer hit him like a lot of bricks, making him flush. That fucker was using his foot to play with Grillby across the table so Papyrus wouldn’t know.

Sans shifted slightly, and his foot slid along the side of his bulge tantalizingly. Grillby was mad, angry even, but…after all that teasing, finally having something touching his neglected cock was…exquisite.

Grillby tilted his head to sneak a peek at Papyrus, who was practically in heaven eating his spaghetti. Taking the chance and practically sprinting with it, Grillby gently canted his hips into Sans’ foot, making them both gasp.

Grillby froze, paranoid that Papyrus heard, but Sans ground his foot harder against him, making him throw his head back against the wall of their booth, groaning.

Papyrus chuckled between a forkful of food. “I know, Grillby! The food here is so good! It’s practically orgasmic!”

“heh, that it is bro, that it is.” The butt plug started up, making Grillby curse softly.

The pleasure from the vibrator and Sans rubbing against his crotch was too much. Way too much. The coil in the pit of Grillby’s stomach was getting harder and harder to ignore. He was going to come right in front of all these people, he knew it. He was going to coat the underside of this table with his cum, and there was nothing he could do about it.

“…I have to go get some air!” Grillby blurted out, the last bit of his sanity forcing him to grab his jacket and flee the table. Ignoring the protests, he just about ran out the door.

Outside, Grillby swiveled to and fro, trying to figure out which way to go, before taking off to the left. He walked around the side of the building, finding a small, dark alleyway. He rested against the wall, running his hands down the front of his pants. His bulge twitched violently as he unzipped them, hissing in bliss as he freed his boner.

A very small part of him reminded him that he was about to masturbate out in public, and that he was a very bright monster in a very dark alleyway, but all his body could process was the way his hand enveloped his cock and how _perfect_ it felt as he thrusted into it.

Before he could get too far into it, a bony hand stopped his hips. Teeth pressed against his mouth as a cool tongue asked for entrance. Grillby opened his mouth, tangling their tongues together as he slowly opened his eyes. Papyrus stared back at him, orange blush dusting his face. With a wink, he pulled Grillby away from the wall, changing their positions so that Papyrus was flush against the wall and Grillby was hovering over him.

After a few moments of furious making out, Papyrus pulled away, kneeling so he was level with Grillby’s cock.

“Nyeh, you’re practically dripping down here! For once, that lazy brother of mine did a good job!” Papyrus exclaimed, starry-eyed.

Grillby gaped at Papyrus. “…Wait, you knew about it?”

“Knew about it? I'm the one who gave Sans the idea.” Papyrus laughed. “I know a lot about you, Grillby. Even the things you don’t tell me.” Papyrus stuck out his tongue, flicking the head of Grillby’s dick. Grillby exhaled, gazing in wonder as he rested his hand on Papyrus’ head.

Giving Grillby’s cock a quick kiss, Papyrus opened his jaw wide and took the entire length into his mouth, conjuring a throat to constrict around it. He moaned appreciatively around the dick, as if thanking Grillby for the opportunity to suck it. Grillby tightened his hold on Papyrus’ skull, trying to pull him closer to fuck his mouth. Papyrus contemplated him for a quick second, before pulling back.

“Ahh, no matter what bet Sans set for this challenge, I’m pretty sure I’m the big winner here. I get to see you in a suit, looking positively _wrecked._ ” Papyrus pulled slightly on his cock for emphasis, gushing at Grillby’s state. “I want to keep you all to myself, but…”

A small _thud_ rang out as a crate was placed on the ground behind Grillby.

“but he should share with me,” Sans growled behind him, pulling his pants down and stepping up on the crate.

Grillby shivered, half from the temperature change and half from the tone of Sans’ voice. It struck him as absolutely _primal_ , and he loved it.

Sans’ hand teased around Grillby’s backside, circling the base of the dildo, before twisting it out of his asshole. Grillby cried out, the suddenness of toy exiting causing him to spurt precum onto Papyrus’ suit top.

“…F-fuck, sorry.” He wanted to say more, but the intrusion of Sans’ lubed up fingers left him breathless.

“trust me, pap is gonna be much dirtier after this, isn’t that right, bro?” Papyrus giggled, putting Grillby’s cock back into his mouth as an answer.

Grillby rested his hands on the wall in front of him, bracing himself as Sans’ fingers left him. His mind was a mess of static as Papyrus’ tongue worked him over, his technique flawless. Sans’ dick nudged against Grillby’s entrance, rubbing against it before slowly pushing in.

Sans thrusted himself into the hilt, running his hands along Grillby’s back as he let him adjust, making the fire elemental whine. He reached an arm around his back to latch onto Sans.

“…Please, I’m so close, I can’t take it anymore. Fuck me hard.”

“well, you heard the man, pap.”

Pulling his cock out slightly, Sans kissed Grillby’s back before plunging back in suddenly, setting a bruising pace. Grillby moaned wantonly, his hips jerking hard enough to shove his length even further down Papyrus’ throat, making him let out a choking sound. Grillby wanted to ask if he was okay, but Papyrus gurgled happily, bracing himself against the wall for the face-fucking.

Grillby knew he wasn’t going to last much longer. He gripped Papyrus’ skull, managing to throw out a small warning before he exploded down Papyrus’ throat, his cum staining the inside of Papyrus’ suit as it slid down his ribcage. The force of his orgasm caused him to clench hard around Sans’ length, and with a loud groan Sans came, coating Grillby’s walls with his cum.

Sans pulled out of Grillby, tucking his penis back into his pants. Without anything to hold him up, Grillby legs gave out, sending him to the ground. Papyrus was instantly on him, checking him over for injuries.

Grillby waved a hand nonchalantly as he rested his head in Papyrus lap. He idly observed the way Papyrus’ suit was slowly turning darker from his cum sliding down the inside of it. “...My body is just remembering how to work again. You two really let me have it.”

Sans sat down next to the two of them, enjoying the post-orgasm haze. They sat in comfortable silence, enjoying the other’s presence, until Grillby lifted his head in horror.

“…I left without finishing my food, or paying, or anything.”

“oh don’t worry, i already paid and took the food home. since neither of us won tonight that seemed like a good consolation prize.” Sans winked. “let’s get out of here and continue this at home, shall we?”

The three of them disappeared, leaving behind an empty alleyway and a suspicious bright puddle.

 

**Author's Note:**

> Thanks for reading! I super appreciate it <3 Feel free to come bother me with comments/feedback/animal pics at my tumblr: :[Sesurescue](http://Sesurescue.tumblr.com)


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